A multi-compartment magnetic capsule robot based on mixed magnetic particles and a driving and controlling method thereof

Abstract

The application belongs to the field of magnetic capsule robots, and specifically discloses a multi-compartment magnetic capsule robot based on mixed magnetic particles and a driving control method. The application introduces a mixed magnetic particle strategy into the valve control components of each compartment of the capsule robot, and sets different gradient mixing ratios, so that different opening thresholds are formed in each component after magnetization. This solves the fundamental problem of the prior art that relies on complex external programming and unstable sequential opening. Therefore, when a uniform and gradually increasing external magnetic field is applied, each compartment can automatically and stably open in sequence based on its threshold. In addition, the opening threshold can be reduced by applying a reverse reconstruction pulse magnetic field to achieve adjustable threshold. Therefore, the scheme converts the sequential control logic from external field programming to a designed and predictable internal material gradient, thereby ensuring the reliability and repeatability of sequential opening and providing a solid foundation for precise time sequence drug delivery.

Description

Technical Field

[0001] This application belongs to the field of magnetically controlled capsule robots, specifically relating to a multi-compartment magnetically controlled capsule robot based on hybrid magnetic particles and its driving and control method. Background Technology

[0002] With the increasing global aging population and the continued growth in the number of patients with chronic diseases, drug therapy has become an important means of improving health and prolonging survival. Especially in the treatment of chronic diseases such as cancer, diabetes, and digestive system diseases, sustained drug release, precise delivery, and multi-stage sequential drug administration are of great significance. Traditional oral and injectable drug delivery methods often suffer from uneven drug release, difficulty in precisely controlling local concentrations, limited duration of therapeutic effect, and poor patient compliance. Therefore, non-invasive, precise, and efficient drug delivery systems have gradually become a research hotspot.

[0003] Magnetically controlled capsule robots, as a novel non-invasive drug delivery platform, rely on the interaction between an external magnetic field and the magnetic functional units inside the capsule to achieve movement, positioning, targeted release, tissue sampling, and other medical functions within the body. They offer advantages such as non-contact control, high biocompatibility, and strong environmental adaptability. Compared to traditional invasive treatments, magnetically controlled capsule robots significantly reduce the burden on patients and show promising application prospects in the field of local gastrointestinal treatment.

[0004] However, most existing magnetically controlled capsule systems employ a single-compartment design, with drug release typically relying on a single valve control unit and a single magnetic field triggering method, making it difficult to meet the needs of multi-dose, multi-timepoint, and staged drug delivery. Although some studies have attempted to use multi-compartment structures to achieve multiple releases, different compartments often struggle to establish stable and distinguishable opening thresholds under the same external magnetic field conditions, leading to problems such as unstable opening sequence, narrow response windows, and excessively high driving magnetic fields. In particular, most existing multi-compartment magnetically controlled capsules utilize a single magnetic material system or simple structural differences to achieve hierarchical control, resulting in limited differences in valve frame-valve leaf adsorption between different compartments, thus making it difficult to construct a stable and reliable sequential opening mechanism.

[0005] Furthermore, relying solely on increasing the amplitude of the external driving magnetic field to sequentially open different compartments will not only increase system energy consumption, but also hinder precise control under low-field conditions and the safety of in-vivo applications. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this application aims to provide a multi-compartment magnetically controlled capsule robot based on hybrid magnetic particles and its driving and control method. The goal is to solve the technical problems that current multi-compartment capsule robots have difficulty in accurately implementing sequential opening mechanisms, which cannot meet the needs of multi-dose, multi-time point, and staged drug delivery, resulting in poor drug delivery effects.

[0007] The first aspect of this application relates to a multi-compartment magnetically controlled capsule robot based on hybrid magnetic particles, comprising: a capsule shell, and multiple independent compartments disposed inside the capsule shell; each compartment is provided with a channel for material exchange and a valve control component for controlling the opening and closing of the channel; each valve control component contains hybrid magnetic particles in different proportions, and after magnetization, each valve control component has a different opening threshold; the capsule robot is configured to open the multiple independent compartments sequentially in a preset order under the action of an external magnetic field based on the different opening thresholds.

[0008] In one embodiment, the valve control component includes: a valve leaf and a valve frame that cooperate with each other; in an initial state, the valve leaf and the valve frame are attracted together, and the corresponding chamber of the valve control component is closed; when the external magnetic field is greater than the opening threshold of the valve control component, the valve leaf and the valve frame overcome the attraction, and the corresponding chamber of the valve control component is opened; wherein, the valve frame contains a preset proportion of mixed magnetic particles, and / or, the valve leaf contains a preset proportion of mixed magnetic particles.

[0009] In one embodiment, when the valve leaf or valve frame contains mixed magnetic particles, it is composed of a composite of mixed magnetic particles and an elastomer matrix.

[0010] In one embodiment, the mixed magnetic particles include: semi-hard magnetic particles and hard magnetic particles; the ratio of the mixed magnetic particles is the ratio of semi-hard magnetic particles to hard magnetic particles.

[0011] In one embodiment, the semi-hard magnetic particles are AlNiCo particles; the hard magnetic particles are NdFeB particles; and the elastomer matrix is ​​Ecoflex 00-30.

[0012] In one embodiment, the opening threshold is determined by the remanence and coercivity of the valve control component; wherein, each valve control component has different remanence and coercivity after being magnetized due to different proportions of mixed magnetic particles.

[0013] In one embodiment, the opening threshold can be reduced by adjusting the mixing ratio of the valve leaf or valve frame containing mixed magnetic particles to control the residual magnetism of the valve control component or by applying a reconstructed magnetic field to the valve frame containing mixed magnetic particles after initial magnetization; wherein the amplitude of the reconstructed magnetic field is less than the threshold that causes the overall magnetization direction of the valve frame to reverse, and the direction is opposite to the initial magnetization direction.

[0014] The second aspect of this application relates to a drive and control method, comprising: driving a capsule robot to move in a target environment to complete positioning and attitude adjustment; after positioning and attitude adjustment are completed, applying an alternating driving magnetic field with gradually increasing amplitude to cause the valve control components of different compartments to open sequentially in a target order; and closing the different compartments by stopping the application of the alternating driving magnetic field.

[0015] In one embodiment, the process of driving the capsule robot to move in the target environment and complete positioning and attitude adjustment includes: initially magnetizing the valve control components so that each compartment has different magnetic properties based on different proportions of mixed magnetic particles; and determining the opening threshold of each compartment based on the different magnetic properties of each compartment to obtain the target sequence.

[0016] In one embodiment, the valve control assembly is initially magnetized, and then the following steps are taken: applying a reverse reconstruction magnetic field of a preset amplitude to each valve frame containing mixed magnetic particles, so that the residual magnetism of the valve frame is weakened but the overall magnetization direction remains unchanged, thereby reducing the opening threshold.

[0017] Overall, the technical solutions conceived in this application have the following beneficial effects compared with the prior art: The technical solution proposed in this application achieves precision, stability and simplification of the multi-compartment sequential drug delivery mechanism through collaborative innovation in structural design and material design, thereby effectively solving the problems of difficult control and poor effect of multi-compartment sequential drug delivery in the prior art.

[0018] Specifically, by employing a key technological approach—incorporating mixed magnetic particles in varying proportions into the valve control components of multiple independent compartments—each valve control component, after magnetization, can form different opening thresholds determined by the inherent physical property of the material composition. This design means that the opening sequence of the multiple compartments no longer relies on complex external magnetic field programming to forcibly differentiate them, but is internalized and pre-defined within the robot's own material properties. Therefore, when a uniform, gradually increasing external driving magnetic field is applied to the capsule robot, each compartment can automatically and stably open sequentially according to a preset order, based on its built-in, differentiated opening threshold.

[0019] Compared with existing technologies, this solution shifts the logic of sequential control from complex external field strength-timing programming to a designable and predictable material parameter gradient, thereby fundamentally ensuring the stability and repeatability of sequential activation, making multi-dose, staged precise timing drug delivery possible, and significantly improving the drug delivery effect. Attached Figure Description

[0020] Figure 1 A schematic diagram of the overall structure of a three-compartment magnetically controlled capsule robot based on hybrid magnetic particles provided in this application embodiment; Figure 2 This is a schematic diagram of the internal cross-sectional structure of the three-compartment magnetically controlled capsule robot provided in an embodiment of this application; Figure 3 This is a schematic diagram of the initial magnetization direction of the valve blade and valve frame provided in an embodiment of this application; Figure 4 A schematic diagram illustrating the compartment opening principle provided in this application embodiment; Figure 5 This is a diagram showing the hierarchical driving and sequential response relationship of alternating magnetic fields provided in an embodiment of this application. Figure 6 A diagram showing the results of the time-sharing release process provided in an embodiment of this application; Figure 7 This is a schematic diagram of the reverse reconstructed magnetic field pulse waveform and the principle of threshold control provided in the embodiments of this application; Figure 8 The actual release process result diagram of the adjustable opening threshold provided in the embodiments of this application; Figure 9 This is a flowchart illustrating the drive control method provided in an embodiment of this application.

[0021] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1 is the first compartment; 2 is the second compartment; 3 is the third compartment; 4a is the valve leaf of the first compartment; 4b is the valve leaf of the second compartment; 4c is the valve leaf of the third compartment; 5 is the capsule shell; 6a is the valve frame of the first compartment; 6b is the valve frame of the second compartment; 6c is the valve frame of the third compartment; 7 is the material exchange channel. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0023] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A existing alone, A and B existing simultaneously, and B existing alone. In this application, the symbol " / " indicates that the related objects are in an "or" relationship, for example, A / B means A or B.

[0024] In this application, the terms "first" and "second," etc., are used to distinguish different objects, not to describe a specific order of objects. For example, "first response message" and "second response message," etc., are used to distinguish different response messages, not to describe a specific order of response messages.

[0025] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0026] In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more, for example, multiple processing units means two or more processing units, multiple elements means two or more elements, etc.

[0027] Current multi-compartment capsule robot sequential opening mechanisms are difficult to achieve precisely, failing to meet the needs of multi-dose, multi-time-point, and staged drug delivery. Therefore, this application proposes an embodiment of a multi-compartment magnetically controlled capsule robot based on hybrid magnetic particles.

[0028] It should be noted that hybrid magnetic particles refer to composite materials composed of two or more particles with different magnetic response characteristics, such as a combination of hard magnetic particles and soft magnetic particles, or a mixed system of magnetic particles with different particle sizes and different coercivity, which can achieve selective triggering through the difference in parameters of the external magnetic field.

[0029] It should be noted that the structure of the multi-compartment magnetically controlled capsule robot includes a capsule shell, multiple independent compartments inside the shell, and opening actuators corresponding to each compartment.

[0030] It should be noted that "multiple compartments" refers to at least two independent compartments located inside the capsule shell. Each compartment is physically separated, with no connecting passages between them, ensuring that the contents, such as medications and diagnostic reagents, do not come into contact with or mix before opening. "At least two" means the minimum number of independent compartments is two, but can be set to two, three, four, or more depending on the drug administration requirements.

[0031] Specifically, please refer to Figure 1 , Figure 1 This is a schematic diagram of the overall structure of a three-compartment magnetically controlled capsule robot based on hybrid magnetic particles, provided as an embodiment of this application. The following embodiments use three compartments as an example.

[0032] In this embodiment, the three-compartment magnetically controlled capsule robot includes: a capsule shell 5, and multiple independent compartments disposed inside the capsule shell 5, namely the first compartment 1, the second compartment 2 and the third compartment 3 in the figure.

[0033] It should be noted that the capsule shell 5 constitutes the main protective structure of the robot, and its material must be biocompatible and tolerant of the digestive tract environment. Its shape is typically designed as a cylinder or a streamlined shape with semi-circular ends to facilitate swallowing and smooth movement within the gastrointestinal tract. The internal first compartment 1, second compartment 2, and third compartment 3 are arranged axially sequentially or radially in parallel, with physical isolation between each compartment. The internal volume of each compartment can be designed to range from 0.5 ml to 2 ml depending on drug loading requirements, and the inner wall can be coated with an anti-adhesion coating to prevent drug residue.

[0034] It should be noted that each compartment is equipped with a channel for material exchange and a valve control assembly for controlling the opening and closing of the material exchange channel 7. Each valve control assembly contains a different proportion of mixed magnetic particles, which, after magnetization, give each valve control assembly a different opening threshold.

[0035] Understandably, the channels for substance exchange in each compartment typically refer to micropores, nozzles, or grid structures located on the sidewalls or ends of the capsule shell. Their function is to allow the contents within the compartment to be discharged under pressure differential or gravity, or to exchange substances with the external environment. The valve control assembly that controls the opening and closing of these channels is the core actuator for achieving precise drug delivery.

[0036] It is understandable that hybrid magnetic particles refer to composite materials made by mixing two or more magnetic materials with different magnetic physical properties (such as coercivity, remanence, permeability, and saturation magnetization) in a specific ratio. Different ratios of hybrid magnetic particles mean that the proportions of various magnetic materials in the valve control components of the first, second, and third compartments are different. Due to the different proportions, the overall macroscopic magnetic response characteristics of the composite material, i.e., the opening threshold, will differ. Here, the opening threshold specifically refers to the critical strength or critical frequency of the external magnetic field required to trigger the mechanical action of the valve control component. For example, the valve control component of the first compartment can be set to a high threshold (requiring a strong magnetic field to trigger), the second compartment to a medium threshold, and the third compartment to a low threshold, or the threshold levels of each compartment can be flexibly adjusted according to the order of opening required clinically.

[0037] At this point, the capsule robot is configured to open multiple compartments sequentially in a preset order under the influence of an external magnetic field, based on different opening thresholds.

[0038] Understandably, the external magnetic field is typically generated by an array of electromagnetic coils worn or fixed outside the patient's body. This magnetic field can be a static gradient magnetic field, an alternating magnetic field, or a rotating magnetic field. When the external magnetic field is applied to the human body, the valve control components of each compartment are simultaneously subjected to magnetic force. Since each component has a different opening threshold, only valve control components with thresholds lower than the current external magnetic field strength will activate, thereby opening the corresponding compartment's passage. By precisely controlling the intensity, frequency, or duration of the external magnetic field through external devices, and varying it in a stepwise manner—for example, by gradually increasing the magnetic field strength from low to high—multiple compartments can be opened sequentially according to a preset magnetic field gradient and different opening thresholds. The timing accuracy of this process can be controlled at the second level, and the opening order can be flexibly configured by adjusting the threshold ratio of each compartment.

[0039] Further, please refer to Figure 2 , Figure 2 This is a schematic diagram of the internal cross-sectional structure of the three-compartment magnetically controlled capsule robot provided in the embodiments of this application.

[0040] As can be seen, the valve control assembly includes: valve blades and valve frames that cooperate with each other, namely, valve blade 4a and valve frame 6a of the first compartment that cooperate with each other, valve blade 4b and valve frame 6b of the second compartment that cooperate with each other, and valve blade 4c of the second compartment and valve frame 6c of the second compartment that cooperate with each other.

[0041] Understandably, the cooperating valve leaf and valve frame constitute a miniature mechanical fluid control switch, essentially equivalent to a controllable gate installed at the outlet of each compartment. The valve frame, as a fixed base, is typically integrally formed or tightly fitted with the inner wall of the capsule shell or the partition plate between compartments, with a central opening for material entry and exit. The valve leaf, acting as a movable baffle, is movably connected to the valve frame via a miniature slide rail, rotating shaft, or flexible hinge structure, enabling translation or rotation at a microscopic scale. In the initial state, to prevent leakage of active material from the compartment, the contact surfaces of the valve leaf and valve frame need to be precision polished or have polymer sealing gaskets added to ensure high-precision surface or line contact, thereby achieving a reliable physical seal.

[0042] It should be noted that in the initial state, the valve leaf and valve frame are attracted to each other, and the corresponding compartment of the valve control component is closed; when the external magnetic field is greater than the opening threshold of the valve control component, the valve leaf and valve frame overcome the attraction, and the corresponding compartment of the valve control component opens.

[0043] Understandably, in the initial state, the adsorption between the valve vane and the valve frame refers to the mutual attraction between them at the microscopic interface, which causes the valve vane to adhere tightly to the valve frame and close the channel. When the external magnetic field is greater than the opening threshold of the valve control component, the valve vane and valve frame overcome the adsorption. This means that when the strength of the externally applied magnetic field reaches a certain critical value, i.e., the opening threshold, the magnetic torque experienced by the mixed magnetic particles in the magnetic field increases accordingly. When the component of this magnetic torque along the opening direction exceeds the initial adsorption force mentioned above, the mechanical balance is broken, the valve vane separates from the valve frame instantaneously or gradually, the channel is opened, and the compartment opens accordingly.

[0044] The valve frame contains a predetermined proportion of mixed magnetic particles, and / or the valve vane contains a predetermined proportion of mixed magnetic particles. This defines the layout of the magnetically sensitive material on the valve control assembly, providing flexible engineering design space for sequential opening of multiple compartments.

[0045] Specifically, the first scenario involves only the valve frame containing mixed magnetic particles, while the valve vane is made of a single magnetic material. In this case, an external magnetic field acts on the valve vane, and the attractive force between the valve control components is controlled by adjusting the mixing ratio of the magnetic particles in the valve frame. The second scenario involves only the valve vane containing mixed magnetic particles, while the valve frame is made of a single magnetic or non-magnetic material. In this case, the valve vane, as a directly force-bearing component, displaces in the magnetic field to detach from the valve frame, and the attractive force between the valve frame components can be controlled by adjusting the mixing ratio of the magnetic particles in the valve vane. The third scenario involves both the valve vane and the valve frame containing mixed magnetic particles. By adjusting the mixing ratio or magnetization direction, they are initially attracted to each other (achieving locking), but under a specific external magnetic field, they repel each other or are flipped by torque, thus achieving rapid opening. These three methods can be applied independently or in combination to the first, second, and third compartments to achieve differentiated opening threshold settings.

[0046] It should be noted that if non-magnetic materials are used, the initial adsorption needs to be achieved by pre-tightening that can replace traditional magnetic adsorption, such as mechanical pre-tightening force, fluid surface tension, or material interface force.

[0047] In this embodiment, through collaborative innovation in structural and material design, the multi-compartment sequential activation mechanism is made accurate, stable, and simplified, thereby effectively solving the problems of difficult control and poor effect of multi-compartment sequential drug delivery in the prior art.

[0048] Specifically, by employing a key technological approach—incorporating mixed magnetic particles in varying proportions into the valve control components of multiple independent compartments—each valve control component, after magnetization, can form different opening thresholds determined by the inherent physical property of the material composition. This design means that the opening sequence of the multiple compartments no longer relies on complex external magnetic field programming to forcibly differentiate them, but is internalized and pre-defined within the robot's own material properties. Therefore, when a uniform, gradually increasing external driving magnetic field is applied to the capsule robot, each compartment can automatically and stably open sequentially according to a preset order, based on its built-in, differentiated opening threshold.

[0049] Compared with existing technologies, this solution shifts the logic of sequential control from complex external field strength-timing programming to a designable and predictable material parameter gradient, thereby fundamentally ensuring the stability and repeatability of sequential activation, making multi-dose, staged precise timing drug delivery possible, and significantly improving the drug delivery effect.

[0050] Furthermore, this embodiment provides a feasible implementation method. When the valve leaf or valve frame contains mixed magnetic particles, it is composed of a composite of mixed magnetic particles and an elastomer matrix. The mixed magnetic particles include semi-hard magnetic particles and hard magnetic particles; the ratio of the mixed magnetic particles is the ratio of semi-hard magnetic particles to hard magnetic particles. Specifically, the semi-hard magnetic particles are AlNiCo particles; the hard magnetic particles are NdFeB particles; and the elastomer matrix is ​​Ecoflex 00-30.

[0051] It is understandable that composites refer to the physical blending process in which mixed magnetic particles are uniformly dispersed in a three-dimensional cross-linked network of an elastomer matrix to form a functional composite material that combines magnetic response characteristics and flexibility. The magnetic properties of the composite material are determined by the type and ratio of the mixed magnetic particles, while the mechanical properties are determined by the cross-linking density, molecular weight and filler dispersion of the elastomer matrix. This can meet the deformation recovery and sealing requirements of valve control components at the miniaturized scale.

[0052] It is understood that semi-hard magnetic particles refer to magnetic material particles with coercivity between 1 kA / m and 100 kA / m; hard magnetic particles refer to magnetic material particles with coercivity greater than 100 kA / m. The ratio of mixed magnetic particles refers to the mass ratio of semi-hard magnetic particles to hard magnetic particles. By adjusting the ratio, differentiated designs of the opening threshold of valve control components in different compartments can be achieved.

[0053] Specifically, the capsule shell 5 is preferably made of photosensitive resin or other biocompatible polymer materials, with an outer diameter of 10 mm, a length of 28 mm, and a wall thickness of 0.5 mm. Three compartments are arranged sequentially along the axial direction inside the capsule shell, with adjacent compartments separated by a non-magnetic partition. The partition thickness is preferably 0.5 mm to reduce magnetic field coupling interference between compartments. Each compartment has a substance exchange channel 7 at its bottom, with a preferred diameter of 0.8 mm, which can be set within the range of 0.6 mm to 1.0 mm depending on the viscosity or release rate requirements of the contents.

[0054] Specifically, the valve leaf is prepared by combining hard magnetic particles and an elastomer, preferably by combining NdFeB hard magnetic particles with Ecoflex 00-30, with a total magnetic powder mass fraction preferably of 60 wt%. After radial magnetization, the valve leaf has stable remanence and can undergo periodic vibration under the action of an applied axial alternating magnetic field. The valve frame is prepared by combining semi-hard magnetic particles and hard magnetic particles with an elastomer, preferably by combining AlNiCo semi-hard magnetic particles and NdFeB hard magnetic particles in an Ecoflex 00-30 matrix, with a total magnetic powder mass fraction also preferably of 60 wt%.

[0055] Specifically, in the valve frames corresponding to the first, second, and third compartments, semi-hard magnetic particles account for 100%, 80%, and 50% of the total magnetic powder mass fraction, respectively, with the remainder being hard magnetic particles. By adjusting the ratio of semi-hard magnetic particles to hard magnetic particles, different valve frames in different compartments achieve different remanence and different valve frame-valve leaf attraction forces under saturated magnetization, thereby establishing the threshold gradient required for sequential response. Specifically, the remanence of the three valve frames under saturated magnetization is 17 mT, 20 mT, and 25 mT, respectively, and the coercivity is 110 mT, 250 mT, and 500 mT, respectively.

[0056] Further, please refer to Figure 3 , Figure 3 This is a schematic diagram of the initial magnetization direction of the valve blade and valve frame provided in an embodiment of this application. In the initial state, the valve blade is magnetized radially outward, and the valve frame is magnetized axially downward. Under the action of residual magnetism, the two form a stable adsorption, so that the material exchange channels of the three compartments are in a sealed state.

[0057] It is understandable that the opening threshold is determined by the remanence and coercivity of the valve control components; among them, each valve control component has different remanence and coercivity after being magnetized due to different proportions of mixed magnetic particles.

[0058] Understandably, the opening threshold refers to the minimum external magnetic field strength or magnetic gradient force required, macroscopically speaking, to overcome the initial sealing force between the valve leaf and the valve frame and open the channel. From a microscopic magnetic physics perspective, this threshold directly depends on two intrinsic magnetic parameters of the functional material of the valve control component: remanence and coercivity. Remanence determines the self-sustaining magnetization level of the valve control component in the absence of external magnetic field interference, directly affecting its stability in maintaining the locked state; coercivity reflects the material's ability to resist external reverse magnetic field interference, determining the energy barrier required for the valve control component to undergo magnetic moment reversal or demagnetization. These two parameters together construct the macroscopic hysteresis loop of the valve control component, giving each valve control component a unique magnetic fingerprint characteristic, thus determining its critical trigger point for mechanical response in an external alternating magnetic field or gradient magnetic field.

[0059] Further, please refer to Figure 4 , Figure 4This is a schematic diagram illustrating the compartment opening principle provided in this application embodiment. By comparing the longitudinal axis driving magnetic field with the red dashed line opening magnetic field, and combining the state differences between the upper and lower capsule robots, the magnetic field threshold control logic is clearly explained: When an axial alternating driving magnetic field is applied, the valve leaf vibrates under the action of magnetic torque. When the driving magnetic field strength is greater than the opening magnetic field, the corresponding function of the black valve control component in the device is activated in an ordered opening state; when the driving magnetic field is less than the opening magnetic field, the corresponding function is not activated in a disordered closing state. The red curve, as the dynamic response boundary of the driving magnetic field, further demonstrates the characteristic of the device state reversal when the driving magnetic field crosses the opening threshold. This mechanism can support precise state control in fields such as magnetic switches and magnetic devices.

[0060] In the preferred embodiment, please refer to Figure 5 and Figure 6 , Figure 5 This is a diagram showing the hierarchical driving and sequential response relationship of alternating magnetic fields provided in an embodiment of this application. Figure 6 This is a diagram illustrating the time-sharing release process results provided in an embodiment of this application. Figure 5 As shown, the peak values ​​of the external magnetic field are Ba1 < Ba2 < Ba3, achieving the following sequentially: Figure 6 The diagram shows the opening of a single position, two positions, and three positions.

[0061] Specifically, the first chamber opens when the external magnetic field peak reaches 11.5 mT; the second chamber opens when the external magnetic field peak reaches 15.4 mT; and the third chamber opens when the external magnetic field peak reaches 24.3 mT. The opening sequence of the three chambers is consistent with their adsorption force gradient, and the response process is stable and repeatable.

[0062] It should be noted that the opening threshold can be reduced by adjusting the mixing ratio of the valve leaf or valve frame containing mixed magnetic particles to control the residual magnetic intensity of the valve control component, or by applying a reconstruction magnetic field to the valve frame containing mixed magnetic particles after initial magnetization; wherein, the amplitude of the reconstruction magnetic field is less than the threshold that causes the overall magnetization direction of the valve frame to reverse, and the direction is opposite to the initial magnetization direction.

[0063] It is understandable that remanence refers specifically to the residual magnetization of the valve leaf after it has experienced an initial external magnetization field, and when the external field is removed. Adjustment refers to changing the degree of alignment or exchange coupling between the magnetic domains of hard and semi-hard magnetic particles inside the valve leaf through physical or chemical means, thereby altering its macroscopic remanence value. In practical applications of magnetically controlled capsules, the valve leaf's opening threshold is positively correlated with its remanence: the lower the remanence, the smaller the magnetization force experienced by the valve leaf in an external magnetic field, requiring only a lower intensity external magnetic field to overcome the initial sealing force and open.

[0064] It is understandable that if the valve leaf is made of mixed particles, the remanence of the valve leaf can be controlled by adjusting the mixing ratio of the valve leaf, thereby controlling the adsorption between the valve leaf and the valve frame, and thus adjusting (mainly reducing) the opening threshold. This is different from the adjustment of the opening threshold by reconstructing the magnetic field mentioned later. One is achieved by adjusting the material design during capsule preparation, while the other is achieved by controlling the magnetization state after capsule preparation is completed.

[0065] Understandably, initial magnetization refers to applying a strong pulsed magnetic field of 1T to 3T during the production stage or before use, causing the magnetic domains of the mixed magnetic particles inside the valve frame to align in the same direction, reaching a near-saturated magnetization state; reconfiguration magnetic field refers to applying an additional pulsed magnetic field of a specific amplitude after the initial magnetization is completed, the function of which is to change the orientation of some magnetic domains inside the valve frame without changing the orientation of its macroscopic magnetic poles.

[0066] Understandably, the amplitude of the reconstructed magnetic field being less than the threshold that would reverse the overall magnetization direction of the valve frame means that this amplitude needs to be precisely controlled between the combined coercivity of the mixed magnetic particles and the magnetic field corresponding to the maximum magnetic energy product. Specifically, this value is typically 30% to 80% of the coercivity, to avoid a 180° flip of magnetic domains leading to a reversal of magnetic poles. Furthermore, the direction being opposite to the initial magnetization direction means that the direction of the magnetic field lines of the reconstructed magnetic field forms a 180° angle with the direction of the magnetic field lines during initial magnetization. Under these parameters, the reconstructed magnetic field will cause some magnetic domains within the valve frame to flip 90° or produce a non-uniform magnetic moment tilt, thereby macroscopically reducing the effective remanence of the valve frame, and consequently reducing the magnetic locking force between it and the valve leaf, ultimately achieving a precise reduction in the opening threshold.

[0067] Specifically, for the second method, please refer to... Figure 7 , Figure 7 This is a schematic diagram of the reverse reconstructed magnetic field pulse waveform and the principle of threshold control provided in the embodiments of this application.

[0068] Understandable, Figure 7 In the middle, the left figure shows three pulse waveforms: "Stage I, Stage II, and Stage III," with the pulse height, i.e., the amplitude of the reconstructed magnetic field, increasing sequentially. At the same time, the red dashed line marked "coercivity" serves as a reference threshold, demonstrating that the intensity of the magnetic field can be graded and controlled by the change in pulse amplitude on the time axis.

[0069] Understandably, the right figure shows the quantitative correlation between the magnitude of the reconstructed magnetic field and the remanence of the material. Observing the elements in the figure: the horizontal axis is "reconstructed magnetic field" and the vertical axis is "remanence". The red curve shows the mapping relationship that the remanence decreases as the amplitude of the reconstructed magnetic field increases. The figure is also divided into "stage I, stage II, and stage III", which correspond one-to-one with the stages in the waveform on the left, reflecting that the suppression effect of reconstructed magnetic fields of different amplitudes on remanence has gradient differences.

[0070] It should be noted that, to reduce the intensity of the external driving magnetic field, this embodiment introduces a controllable magnetic reconfiguration mechanism in the valve frame. By applying a reconfiguration magnetic field opposite to the initial magnetization direction of the valve frame, the residual magnetism of the valve frame is weakened while the overall magnetization direction remains unchanged, thereby reducing the attraction force between the valve frame and the valve blade. The reconfiguration magnetic field is generated by an external coil system, with a preferred peak magnetic induction intensity of 110 mT, a preferred pulse duration of 1 ms to 3 ms, and an amplitude lower than the threshold value required to reverse the overall magnetization direction of the valve frame. After applying this reconfiguration magnetic field, the residual magnetism of each compartment valve frame is further weakened, corresponding to an overall decrease in the opening magnetic field threshold, thereby enabling sequential opening under a lower driving magnetic field.

[0071] Further, please refer to Figure 8 , Figure 8 The diagram shows the actual release process results of the adjustable opening threshold provided in the embodiments of this application.

[0072] Understandably, the unopened compartment shown in the figure opens under the original magnetic field condition of 15 mt after reverse reconstruction. The comparison of the hysteresis loop of the valve frame and the opening magnetic field before and after reverse reconstruction shows that the reconstructed magnetic field can effectively reduce the residual magnetism of the valve frame and lower the opening threshold. Experimental results also indicate that the valve frame-valve blade adsorption force decreases as the effective residual magnetism decreases, and the adsorption force can be adjusted by controlling the strength of the reconstructed magnetic field.

[0073] Understandably, release tests were conducted under alternating magnetic field conditions. Test results showed that the leakage rate was only 0.10% in the sealed state, and the cumulative release amount reached 95.2% in the sequential opening state. Multiple cycle experiments demonstrated that the three-compartment capsule maintained a stable sequential response after 25 cycles of alternating magnetic field loading. Test results showed that the magnetic properties of the valve frame and valve vane retained at 96% and 94%, respectively, indicating that the structure of this application has good repeatability, stability, and environmental adaptability.

[0074] In addition, the external magnetic field driving system of this application adopts a three-dimensional Helmholtz coil structure. This system consists of three pairs of parallel coils, capable of generating an alternating magnetic field with a spatial uniformity of ±3%, a control resolution of 1 mT, a frequency range of 0.5–5 Hz, and a maximum output magnetic field of 30 mT. The experimental platform includes a coil system, a power amplifier module, a signal generator, and a control computer. It should be noted that the embodiments of this application can also be extended to a four-compartment or more-compartment configuration. By adjusting the ratio of semi-hard magnetic particles to hard magnetic particles in the valve frames of different compartments, different remanent magnetization in each valve frame and different opening thresholds are achieved, thereby maintaining sequential response. In a preferred embodiment, a dual-pulse reconstruction mode can also be used to further reduce the remanent magnetization of the valve frames and the opening threshold.

[0075] In summary, this embodiment achieves sequential multi-compartment opening, low-field drive, and stable repetitive response through a multi-compartment structure, a remanent magnetic gradient formed by a valve frame with mixed magnetic particles, and reverse magnetic reconstruction control. Compared with traditional single-compartment magnetically controlled capsules, this application does not rely on a single high threshold for opening, nor on overall magnetization reversal. Instead, it achieves graded response and low-field drive through valve frame remanent magnetic gradient and magnetic reconstruction control.

[0076] Meanwhile, this embodiment achieves multi-compartment time-sequential drug delivery and adjustable activation magnetic field through structural design and material control, offering advantages such as low energy consumption, fast response, and strong controllability. It can be applied not only to drug delivery but also to microfluidic control, staged liquid injection, and biomedical applications requiring time-sequential control in micro-magnetic drive systems.

[0077] Specifically, this implementation introduces a valve frame material system based on a hybrid of semi-hard and hard magnetic particles into a multi-compartment magnetically controlled capsule robot. This creates a designable opening threshold gradient across different compartments, enabling stable sequential opening and time-sharing release under the same external magnetic field driving logic. Furthermore, by incorporating reverse magnetic reconstruction control, the opening magnetic field threshold can be reduced without altering the overall sequential response relationship, achieving lower-field actuation. This solution combines material designability, structural scalability, and control adjustability, making it suitable for multi-stage drug delivery and other time-sharing magnetic actuation applications.

[0078] In addition, this application also proposes an embodiment of a drive control method. Please refer to... Figure 9 , Figure 9 This is a schematic flowchart of the drive control method provided in an embodiment of this application. The drive control method includes steps S10 to S30.

[0079] Step S10: Drive the capsule robot to move in the target environment to complete positioning and attitude adjustment.

[0080] Step S20: After positioning and attitude adjustment are completed, the valve control components of different compartments are opened sequentially according to the target order by applying an alternating driving magnetic field with gradually increasing amplitude.

[0081] Step S30: Close the different compartments by stopping the application of the alternating driving magnetic field.

[0082] It is understood that the driving and control method proposed in this application is a closed-loop control strategy specifically designed for the aforementioned multi-compartment magnetically controlled capsule robot based on hybrid magnetic particles. It aims to achieve precise displacement of the capsule within the body and orderly release of multiple compartments through non-invasive external magnetic field manipulation. The core logic of this method lies in decoupling spatial position control from temporal release control: firstly, step S10 ensures the capsule reaches the predetermined treatment site and is in the optimal release posture, eliminating the risk of opening failure due to improper positioning; then, utilizing the matching relationship between the magnetic field amplitude and the material's magnetic properties in step S20, it achieves cascaded opening of multiple compartments without the need for circuitry; finally, step S30 achieves reversible repositioning of the structure, providing the possibility for repeated drug administration or capsule removal. This process significantly differs from traditional single-function capsule control, providing a systematic solution integrating motion, positioning, release, and closure.

[0083] Specifically, before step S10, the process includes: initially magnetizing the valve control component so that each compartment has different magnetic properties based on different proportions of mixed magnetic particles; and determining the opening threshold of each compartment based on the different magnetic properties of each compartment to obtain the target sequence.

[0084] Understandably, the initial magnetization of valve-controlled components is typically performed externally using a pulsed strong magnetic field. The purpose is to unify the magnetic domain orientation of the magnetic particles in each compartment and establish a stable hysteresis loop. Determining the opening threshold of each compartment based on its different magnetic properties involves establishing a mapping database of mixing ratio, remanence / coercivity, and opening threshold through experimental calibration or finite element simulation, thereby determining the target sequence according to clinical prescriptions.

[0085] Specifically, if it is necessary to reduce the opening threshold, after the initial magnetization of the valve control component, a reverse reconstruction magnetic field of preset amplitude can be applied to each valve frame containing mixed magnetic particles to weaken the residual magnetism of the valve frame but keep the overall magnetization direction unchanged, thereby reducing the opening threshold.

[0086] Understandably, as an optional step, the threshold can be dynamically adjusted before medication: if the high threshold chamber needs to be opened in advance, a reverse magnetic field with an amplitude of 50% of the original coercivity can be applied to weaken the residual magnetism without reversing the magnetic poles, thereby reducing the driving magnetic field strength required for actual opening.

[0087] Compared with the prior art, the beneficial effects of the drive and control method provided in this application are the same as those of the multi-compartment magnetically controlled capsule robot based on hybrid magnetic particles provided in the above embodiments, and will not be repeated here.

[0088] It should be understood that expressions such as “comprising” and “may include” used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as “comprising” and / or “having” are to be interpreted as indicating a particular characteristic, number, operation, constituent element, component, or combination thereof, but not to exclude the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0089] Furthermore, in this application, the expression "and / or" includes any and all combinations of the associated listed words. For example, the expression "A and / or B" may include A, may include B, or may include both A and B.

[0090] It should be noted that the directional terms mentioned in the embodiments of this application, such as "top", "bottom", "inner", "outer", "left", "right", "radial" or "axial", are only for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of this application, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0091] Furthermore, in the embodiments of this application, the mathematical concepts mentioned, such as symmetry, equality, parallelism, reversal, and perpendicularity, are all limitations relative to the current technological level, rather than absolute and strict mathematical definitions. Slight deviations are permissible; approximations of symmetry, equality, parallelism, and perpendicularity are all acceptable. For example, "A and B are parallel" means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 and 10 degrees. "A and B are perpendicular" means that A and B are perpendicular or approximately perpendicular, and the angle between A and B can be between 80 and 100 degrees.

[0092] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A multi-compartment magnetically controlled capsule robot based on hybrid magnetic particles, characterized in that, include: The capsule shell, and a plurality of independent compartments disposed inside the capsule shell; Each of the aforementioned compartments is equipped with a channel for material exchange and a valve control assembly for controlling the opening and closing of the channel; Each of the valve control components contains mixed magnetic particles in different proportions, the mixed magnetic particles including semi-hard magnetic particles and hard magnetic particles; the proportion of the mixed magnetic particles is the ratio of semi-hard magnetic particles to hard magnetic particles. After being magnetized, each of the valve control components has different remanence and coercivity due to the different proportions of the mixed magnetic particles, and thus has different opening thresholds. The capsule robot is configured to open multiple independent compartments in a preset order based on different opening thresholds when a uniform, gradually increasing external driving magnetic field is applied. Furthermore, the opening threshold can also be reduced by applying a reconstruction magnetic field to the magnetized valve control component that is opposite to the initial magnetization direction and has an amplitude smaller than the coercivity, thereby weakening the remanence of the valve control component while keeping the overall magnetization direction unchanged.

2. The multi-compartment magnetically controlled capsule robot based on hybrid magnetic particles as described in claim 1, characterized in that, The valve control assembly includes: a valve leaf and a valve frame that cooperate with each other; In the initial state, the valve leaf and the valve frame are attracted to each other, and the chamber corresponding to the valve control component is closed; when the external magnetic field is greater than the opening threshold of the valve control component, the valve leaf and the valve frame overcome the attraction, and the chamber corresponding to the valve control component opens. The valve frame contains a preset proportion of mixed magnetic particles, and / or the valve leaf contains a preset proportion of mixed magnetic particles.

3. The multi-compartment magnetically controlled capsule robot based on hybrid magnetic particles as described in claim 2, characterized in that, When the valve leaf or the valve frame contains mixed magnetic particles, it is composed of a composite of mixed magnetic particles and an elastomer matrix.

4. The multi-compartment magnetically controlled capsule robot based on hybrid magnetic particles as described in any one of claims 1 to 3, characterized in that, The semi-hard magnetic particles are AlNiCo particles; the hard magnetic particles are NdFeB particles; and the elastomer matrix is ​​Ecoflex 00-30.

5. The multi-compartment magnetically controlled capsule robot based on hybrid magnetic particles as described in claim 2, characterized in that, The opening threshold can be adjusted by regulating the residual magnetic intensity of the valve control component by adjusting the mixing ratio of the valve leaf or valve frame containing mixed magnetic particles.

6. A driving and control method, characterized in that, The application of the multi-compartment magnetically controlled capsule robot based on hybrid magnetic particles as described in any one of claims 1 to 5 includes: Drive the capsule robot to move in the target environment and complete localization and posture adjustment; After positioning and attitude adjustment are completed, the valve control components of different compartments are opened sequentially according to the target order by applying an alternating driving magnetic field with gradually increasing amplitude. By stopping the application of the alternating driving magnetic field, the different compartments are closed.

7. The drive control method as described in claim 6, characterized in that, Driving the capsule robot to move in the target environment, completing localization and posture adjustment, previously included: The valve control components are initially magnetized so that each compartment has different magnetic properties based on different proportions of mixed magnetic particles; The opening threshold of each compartment is determined based on its different magnetic properties in order to obtain the target sequence.

8. The drive control method as described in claim 7, characterized in that, The valve control assembly is initially magnetized, followed by: A reverse reconstruction magnetic field of preset amplitude is applied to each valve frame containing mixed magnetic particles to reduce the residual magnetism of the valve frame but keep the total magnetization direction unchanged, thereby reducing the opening threshold.

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